Mini Split Heat and Air in Syracuse – What is the Difference between Air Barriers and Vapor Barriers?

Air barriers are intended to restrict the flow of air through openings in the walls, ceilings, and floors of a building, while vapor barriers are designed to restrict the flow of water vapors through the same openings. In general terms, air barriers attempt to block incoming air while vapor barriers attempt to block outgoing air. Since air typically carries a significant amount of moisture, air and vapor barriers actually work together in an effort to keep moisture out of houses, buildings, and other structures.

Ductless Heating and Cooling Systems in Syracuse – Air Barriers and Vapor Barriers.

Air typically enters a house or building through gaps in walls, ceilings, and floors. During warm weather when air conditioning is in use, this moist incoming air can become trapped in cavities between exterior and interior walls resulting in undesirable moisture condensation on sheathing and framing members. Air barriers are typically used to prevent this unwanted condensation from occurring. An air barrier may be composed of a continuous sheet of plastic, a spray-type foam insulation, or even a combination of latex caulk and paint.

Mini Split Heat Pump System in Syracuse – New Construction.

Although many local building codes require the use of both air barriers and vapor barriers in new construction, some building codes do not make any distinction between the two. There is however, some controversy among researchers as to whether a vapor barrier is actually even necessary. Some studies have shown that air leakage is often far more responsible for transferring moisture than diffusion is. 

Ductless Air Conditioning Systems in Syracuse – Good Air Barrier.

Many experts believe that the presence of a good air barrier may be more effective against unwanted moisture transfer than a vapor barrier. Until a definite conclusion is reached regarding this subject, a combination of both of these types of barriers may offer the best overall protection against undesired moisture transfer.